1. Field of the Invention
The present invention relates to a plaster containing felbinac and, more particularly, to an anti-inflammatory, analgesic plaster containing felbinac of an anti-inflammatory, analgesic agent as a medicinally effective component for the purpose of curing lumbago, myalgia, periarthritis, and so on.
2. Related Background Art
Felbinac (4-biphenylacetic acid) is an active metabolite of fenbufen, a non-steroid type anti-inflammatory, analgesic agent, and is a drug demonstrating strong anti-inflammatory and analgesic actions. Since this drug is not suitable for oral administration, the attention has been focused on studies on preparations for dermal administration. Gels, liquids, and poultices containing the above-stated drug are commercially available hitherto. The gels and liquids, however, had problems of difficulty in administration in a given quantity, low bioavailability, adhesion to clothing, a number of administrations (for example, several administrations per day), and so on. The poultices have been developed in order to overcome these problems of the gels and liquids, but they still had problems of incapability of affixing them for a long period of time because of their weak adhesion, low bioavailability, and insufficient persistence of the effect of the drug. Japanese Patent Application Laid-Open Gazette No. Hei. 4-321624 proposed an anti-inflammatory, analgesic plaster in which the chief component of the base was a styrene-isoprene-styrene block copolymer and in which crotamiton was an essential solubilizer.